1. Field of the Invention
The present invention relates to acrylic resin compositions which have excellent antistatic property and good appearance, with small decrease of an antistatic property particularly when using a masking film. The present invention is to provide suitable materials for electric and electronic appliances, covers for lighting apparatus, and lens for projection TVs, to which dust may often be adhered.
2. Description of Related Arts
Acrylic resins have been widely utilized in many fields such as electric appliances and household use articles in the form of sheets, molded products, etc., due to favorable characteristics such as lightness in the weight and easy handlings. Although the resins are excellent in electric insulation performance, they have some disadvantages in the charge and accumulation of static electricity. For instance, dust is easily adhered on the surface of the apparatus until the transparency and luster are degraded, the fine appearance is damaged and the commercial values are decreased. In order to cope with such problems, one of approaches is that, to acrylic resins, is added a metal salt of alkylsulfonic acid represented by the formula R--SO.sub.3 M, wherein R is an alkyl group and M is a salt-forming metal such as alkali and alkaline earth metals. However, addition of antistatic agents encounters problems such as decrease in transparency, deterioration in appearance, etc. JP 7-18137A and 7-207088A suggest to blend a specific resin with a particular metal sulfonate salt, in order to dissolve the problems.
Furthermore, the surfaces of thermoplastic resin products are generally masked with, for example, a polyethylene film, in order to protect appearance thereof. Acrylic resin compositions prepared according to the methods mentioned above are, however, not free from disadvantages in remarkable decrease of antistaticity, after a long time contact with the masking film. This would be probably due to migration of the antistatic agent applied on the surface of the compositions to a paste of the masking film. If the paste for masking film is replaced by that which the antistatic agent hardly migrates to, peeling-off of the masking film tends to occur, causing difficulties in maintenance and storage.